Abstract

Search engines return results mainly based on the submitted query; however, the same query could be in different contexts because individual users have different interests. To improve the relevance of search results, we propose re-ranking results based on a learned user profile. In our previous work we introduced a scoring function for re-ranking search results based on a learned User Interest Hierarchy (UIH). Our results indicate that we can improve relevance at lower ranks, but not at the top 5 ranks. In this thesis, we improve the scoring function by incorporating new term characteristics, image characteristics and pivoted length normalization. Our experimental evaluation shows that the proposed scoring function can improve relevance in each of the top 10 ranks.

Abstract

We model a family of peer-reviewing processes as game-theoretic problems. The model helps to understand elements of existing peer-reviewing procedures, and to predict the impact of new mechanisms. The peer-reviewing for evaluation of scientific results submitted to conferences involves complex decision processes of independent participants. Significant tax-payer money is spent by governments for the advancement of science, and such governmental decisions are often based on outcomes of peer-reviewing in scientific conferences. Here we propose to analyze and design improved mechanisms for conference peer-reviewing, based on game-theoretic approaches. Real world conference peer-reviewing processes are overly complex and here we define and analyze a simplified (toy) version, called the Peer-Reviewing Game. While our toy version may have significant assumptions, it provides an interesting game and a first step towards formalizing and understanding the real world problem.

The players of this game are the researchers that participate as authors and reviewers. A funding agency tries to maximize the social value by providing rewards to researchers based on their publications. In this work the conference chair is assumed to be a trusted party, enforcing policies agreed by the funding agency and making publication decisions based on the recommendation of the reviewers. We uncover relations between Peer-Reviewing games and Prisoner's Dilemma games. Examples of mechanisms are described and analyzed both theoretically and experimentally.